the second clip was cool. I don't think that in real life it is possible though, you'd think that a faucet washer or solder joint or something would fail before the tank got up to 350psi.

Working in the fire service for 25 years now, I can tell you from experience that it is absolutely possible in real life. And not just launching through a small shed-like building. The one that I responded to blew from the basement, through the roof of a a two story house, and we never did find the water heater! You could have driven a semi-truck through the hole it left! Fortunately the family wasn't home when it happened. The video about exercising your pressure relief valve is VERY GOOD ADVICE!!